Process for manufacture of tetramethyllead



United States Patent 3,192,244 PROCESS FOR MANUFACTURE OF TETRAMETHYLLEAD Paul Kobetz and Francis M. Beaird, Baton Rouge, La., assignors to Ethyl Corporation, New York, N.Y., a corporation of Virginia No Drawing. Filed Aug. 31, 1962, Ser. No. 220,881 Claims. (Cl. 260437) This invention relates to the manufacture of alkyllead compounds. More particularly, the invention relates to a new and improved process for the manufacture of a tetramethyllead product.

vIt is known that the tetraalkyllead compounds can be made by the reaction of an alkali metal lead alloy and an alkyl halide, particularly, the monosodium lead alloy, NaPb, and the corresponding alkyl chloride. This type of synthesis reaction has been employed for making large amounts of tetraethyllead. The chemical reaction is entirely operative for other tetraalkylleads, and of recent periods considerable interest has developed in the manufacture and use'of tetramethyllead, which is an appreciably more volatile lead antiknock compound.

In the case of tetramethyllead, the yields obtained are not as high as desired. Thus yields of the order of 70 percent are reported, and under carefully controlled laboratory conditions, yields of about 7 7-78 percent can be obtained. Such results are achieved using, for example, a hydrocarbon aluminum compound as a catalyst and in the presence of a small quantity of an inert hydrocarbon liquid. Such liquids, desirably employed in the proportions of about one-twenty-fifth to one-fifth part by weight per part of alloy, serve apparently as adjuvants to the catalyst and provide the above mentioned yields at moderate reaction conditions. Difiiculty is frequently encountered, however, in discharging the product of a reacttion, such reaction masses containing large proportions of subdivided lead metal released by the reaction and sodium chloride formed, as well as the tetramethyllead formed.

' An object of the present invention is to provide a new and improved process for making tetramethyllead. An even more particular object is to provide a new process for making tetramethyllead in high and eificient yields. Another object is to provide an improvement in tetramethyllead manufacture whereby high yields are obtained, and also the discharge of a reaction mass is greatly expedited and the incidence of reactive catalyst component residues in a reaction mass is greatly reduced. An additional object is to provide a new and novel catalyst system having a plurality of at least two components and exhibiting unusual and unexpected properties and attributes.

It has now been discovered that tetramethyllead can be synthesized in the presence of a new catalyst system, and that high yields and other benefits not heretofore available, can be realized. The process of the invention comprises the reaction of sodium lead alloy and methyl chloride in the presence of a catalytic amount of the catalyst system, which in all instances includes an aluminum component and an organic compound having at least one glycol ether grouping therein. The aluminum catalyst is usually a hydrocarbon aluminum compound, but also can be finely subtliveded aluminum metal or an aluminum trihalide such as the trichloride, tribromide, or triiodide. By hydrocarbon aluminum compound is meant those organometallic aluminum compounds having at least one hydrocarbon radical per aluminum atom, the remaining bonds of the aluminum being satisfied by hydrogen, other hydrocarbon radicals or by other radicals or elements which are innocuous or not deterimental to the reaction. As described more fully below, a wide variety of hydrop m m Ice Patented June 29, .1965

carbon aluminum compounds are suitable, including, typically, trialkyl aluminum compounds and numerous others as illustrated herein.

The catalyst system or composition also includes, as stated, an organic compound having at least one glycol ether grouping, this being the group represented by the expression The terminal bonds of a single group are satisfied by hydrocarbon radicals or additional glycol ether groups. The foregoing attribute is found not only in diethers of glycols, but in certain other categories of compounds. Thus among the types of compounds effective as a com ponent of the catalyst system are the lower dialkyl ethers of lower polyethylene glycols, cyclic diethers, dialkoxy lower alkanes, and al-kyl ethers of methyl tetrahydrofuran. Good results are obtained with catalyst systems following the above requirements, viz., having the hydrocarbon aluminum compound plus only one organocompound having the glycol ether grouping, but in certain preferred embodiments, a plurality of the latter components are provided and additional benefits are accrued which are highly valuable in certain environments.

Typical hydrocarbon aluminum compounds which are suitable include trimethyl aluminum, thriethyl aluminum, ethyl aluminum sesquichloride, diethyl aluminum chloride, ethyl aluminum dichloride, tri-n-propyl aluminum, tri-nbutyl aluminum, triisobutyl aluminum, diisobutyl aluminum hydride, triphenyl aluminum, tn'octyl aluminum, di-' ethyl aluminum hydride, diethyl aluminum ethoxide, and others. Generally, then, aluminum compounds having at least one hydrocarbon radical having from one to about ten carbon atoms are fully suitable for use. The simpler alkyl aluminum compounds, such as mentioned illustratively above, are preferred. When desired, the hydrocarbon aluminum catalyst component can be generated in situ, as, for example, by the reaction of an aluminum trihalide with a hydrocarbon compound of another metal. Thus, the reaction of aluminum trichloride and tetraethyllead will generate hydrocarbon aluminum moieties operative as this catalyst component.

The lower dihydrocarb-on ethers of the lower polyethylene glycols are one type of co-catalysts and are similarly not restricted to isolated specimens. The term dihydrocarbon includes both those diethers having two identical hydrocarbon groups, and also those having dissimilar hydrocarbon groups, as, for example, the methyl ethyl ether of diethylene glycol. By lower polyethylene glycol is meant those compounds having in series up to about six or seven glycol groups, i.e.

wherein n is up to about 7. Generally, it is preferred to employ those members of this group having up to and including four such groups or moieties, the ethers of diethylene glycol being especially preferred. The hydrocarbon radicals of these materials can be aryl, cycloalkyl, alkaryl, aralkyl, or similar alkyl groups. Simple alkyl groups of up to ten carbon atoms are preferred, the normal :alkyl groups of one to four carbons being especially preferred.

In carrying out the process, by a batch or cyclic technique, a reaction zone is charged with subdivided solid alloy, usually the monosodium lead alloy, although some variation from this is permissible, and then the co-catalyst system is charged. Various modes of charging can be employed, and for particular catalyst systems, there can -be minor benefits associated with a particular mode. Thus, effective modes include adding separately the alurninum catalyst component and the co-catalyst or synergist portion, or pre-mixing these components, or adding one or both of the components in several increment-s separated by short time intervals.

Frequently, the initial charge also includes an inert liquid hydrocarbon, in limited proportions. Usually, suitable proportions are from about one-twenty-fifth to about one-fifth of the alloy by weight. The hydrocarbon is particularly beneficial according to prior processes using only a hydrocarbon aluminum catalyst, as in such instances, the hydrocarbon results in a greater eifectiveness of single catalyst components. In the present invention, the hydrocarbon is usually optional but generally beneficial. The hydrocarbon promotes the stability of the tetrarne-thyll-ead productafter recovery from the reaction mass. A wide choice is available for selection of an inert liquid hydrocarbon, commercial toluene being a particularly suitable material. As already stated, the use of the hydrocarbon isoptional, and good results are obtained without such a material.

After the above described charge, the reactor is sealed except for necessary venting connections. The. temperature is raised to, usually, at least 65 C. or above, while the system is agitated, and methyl chloride is charged. The methyl chloride in some cases is charged all at one time, and in other cases is fed in over a deliberate finite period. The total methyl chloride is provided in proportions of at least one stoichiometric requirement or theory, and usually, a substantial excess is used. It will be understood that this refers to the total quantity fed during batch operations. During portions of such cyclic operations, only minor quantities of methyl chloride may be present, when the feed is spread out over a finite period.

. The materials thus charged together are then reacted at temperatures averaging from about 85 to 110 C. Agitation is provided throughout the reaction period, .as the reacting system includes solids and volatile liquids. The reaction is continued to completion, requiring from about one hour and less than seven hours, dependent on the configuration of the apparatus, the degree of agitation, and the quantity of alloy to be reacted.

On completion of the reaction, the autoclave and contents are cooled and discharged, and the tetramethyllead is recovered from the lead and alkali metal chloride components of the reaction mass. When small portions of hydrocarbon additive are employed in the synthesis reaction the tetramethyllea-d is usually accompanied on recovery by said hydrocarbon liquid.

As already noted, the present invention provides high yields, in addition to other benefits. eral mode of ope-ration, and the results heretofore obtained, a series of base line operations were conducted, showing generally the procedure already mentioned, except that the only additives or catalysts for the process were. hydrocarbon aluminum compounds, and no components having a glycol ether grouping were provided.

In these operations, in each run, an autoclave was charged with 1,000 parts of comminuted monosodium lead alloy, containing Weight percent sodium. A

mixture of an aluminum type catalyst, dissolved in an hydrous toluene, was then charged, while agitating the contents of the autoclave. The said solution was provided in proportions of about 54 parts toluene by weight, and the aluminum catalyst Was charged in proportions of about 0.24 weight percent aluminum content based on the alloy charged. According to the identity of the aluminum catalysts, of course, the Weight of the catalyst compound would be varied. Thus, in the case ofusing methyl aluminum sesquichloride, (CH Al Cl as the aluminum type catalyst, a typical concentration was about 9.26 parts per 1,000parts of the monosodium lead alloy charged.

The charge thus established was then sealed in the autoclave and preheated to about 95 C., and then methyl chloride was ted to the autoclave interior. The temperature was, controlled below about 110 C., and the methyl To illustrate the gen-' 4; chloride was fed during a period of less than about 30 minutes in proportions corresponding to 1.7 theories, or about 370 parts -by weight per 1,000 parts of the alloy charged.

Upon completion of the reaction, after additional reaction for a period of approximately two hours, the contents of the'autoclave were cooled and removed from the interior. The amount of tetramethyllead produced was determined by its extraction from the reaction mix ture, or reaction mass, with a hydrocarbon solvent and by reaction of the tetramethyllead with iodine of an aliquot of the liquid extract, followed by back titration. Alternatively, in some instances, the reaction mass was subjected .to steam distillation, for separation of the tetramethyllead from the excess lead solids and sodium chloride component of the reaction mass.

A series of operations as above described was carried out, using the procedure indicated and with occasional slight variation in the amount of catalyst provided. Using triethyl aluminum as the catalyst, the average yield in a substantial number of operations obtained was 77.9 percent, and when using methyl aluminum sesquichloride as a catalyst in comparable concentrations, the average yield was 76.8 percent.

The reaction mass attained in the above described base line runs was quite reactive, in that, when portions were exposed to the atmosphere, considerable fuming occurred. The fuming is attributed to the existence in the reaction mass of aluminum hydrocarbon moieties, expressed as AlR. These groups, wherein Al is the monovalent equivalent and R is a hydrocarbon or a hydrogen, are capable of reacting with oxygen and releasing microscopic particles of aluminum oxide. These particles are so fine that they appear as a fog and tend to foul heat exchange surfaces in recovery equipment.

To illustate the operation of the present invention, the following workin examples are given.

Example 1 In this operation, the procedure described for the base line runs was followed, except that the aluminum catalyst, in this case triethyl aluminum, was provided in the proportions of 0.46 weight percent, based on the alloy, and in addition dimethyl ether of diethylene glycol was concurrcently charged, in the proportions of about mole per mole of the triethyl aluminum. This corresponds to a concentration of 0.11 wt. percent aluminum.

Upon completion of the reaction, it was found that a yield of 93 percent of tetramethyllead had been obtained, representing a yield improvement of 15 percent above the results obtained according to the base-line procedure. In addition, inspection of the reaction mass'produced by the process showed that it was not sticky or lumpy, and could be readily discharged from the autoclave without being significantly air-sensitive, viz., did not exhibit fuming when contacted with air.

In the foregoing example, as indicated, the aluminum catalyst plus the dimethyl ether of diethylene glycol were added at substantiallythe same time. In other operations, alternative modes of introducing .the plural catalyst components have been employed. These include the following:

Reverse addition-the synergist co-catalyst is added and thereafter the aluminum catalyst is provided.

Premixed additionin this operation, the aluminum catalyst, and the synergist co-catalyst of the present invention, with or Without a hydrocarbon, are mixed together prior to adding to the autoclave charge.

In other instances, the catalyst system, viz., the aluminum allryl plus the synergist, are added in delays, or increments spaced apart by several minutes, but within the first 15 minutes or one-half hour of reaction. 7 As is exhibited by the following tabulated examples, these various modes of addition are all quite satisfactory.

To illustrate the scope of the present invention more fully, the fiollowing table cites the results obtained in additional working examples, wherein the catalyst system included the hydrocarbon aluminum compound and a dialkyl ether of a lower polyethylene glycol.

6 charged from an autoclave by mechanical means associated therewith. This study showed that from 68 to 72 percent of the reaction mass was discharged following each run, the average being 71.4 percent.

Aluminum hydrocarbon component Lower alkyl ether of lower polyethylene glycol Hydro- TML Increase Example Catalyst carbon, Yield over base Concentration Moles/gm. feed if any percent e, Identity Al, wt. percent Identity atom. Al percent of Alloy (C 11 3A1 0. 12 Dirlnetliyl ether of diethylene 0.5 Reverse Toluene. 89. 6 11.7

o (C2H5)3A1 0. 11 0. 75 Normal--. do---. 81. 2 3. 3 (0 115) 3A1. 0. ll 0. 77 (1 do. 82. 8 4. 9 (C2H5)2A1H 0. 105 0.36 .-.do.. 89.3 11.4 (CgHshAlH-l- 0.12 0. 50 do. .do 90.3 12.4

(C2115) 3A1. (CH3) HALZCIB 0.12 0.69 90. 7 13. 9 (CH3)3A12C13-.. 0. 12 0. 60 89. 8 13. 0 (OHa),aAlzC1a 0. 12 0. 69 90. 6 13. 8 (CHz)aA12Cl3. 0.12 0.69 91. 6 14. 8 (CH3) sAl2Cls. 0. 092 1. 94. 3 l7. 5 (OHahAlzCla 0. 12 0. 53 87. 0 10. 2

(CHa)aAl2Cl3 0. l2 0. 53 90. 1 .13. 3 (C Ha) sAlzCla.-- 0. 12 0. 50 79. 4 2. 6 (CH3)3A1zCl3. 0. 12 d0 1. 50 81.7 4. 9 (CHa)aA.lzCl3 0. 12 Dirlnetliyl ether of tctraethylene 0. 71 88. 5 11.7

' g yeo (CH3)3A11C13 0. 12 Methyll-ethlyl ether of diethyl- 0. 44 Delay.- ---do---- 88. 8 12. 0

ene g yco (CH3)3Al2Cl 0. 12 Dirfletliyl ether of ethylene 0. 51 Normal--- None. 86. 4

g yco The fore-going examples illustrative typical excellent results obtained according to the present process. In addition to the good yields obtained, the ease of op ra i y was clearly increased owing to the fact that the reaction product mixture, or reaction mass is altered in physical properties. This alteration is evidenced not only by the lower chemical reactivity, on exposure to air, which is attained, but also is shown by the ease with which .the material can be dischargedfrom a reaction zone. Reaction mass includes not only the tetramethyllead engendered by the process, but also the substantial quantity of finely divided lead particles resultant from the reaction, sodium chloride obtained as a joint product, and the hydrocarbon liquid when employed. The improvement in processability is shown by the examples below:

Example 19 Seven reactions were carried out according to the When the same operations were repeated, but the catalyst included methyl aluminum sesquichloride and a lower dialkyl ether of a lower polyethylene glycol, substantial improvement in the amount of discharge following each operation was attained. Thus, for the catalyst system, methyl aluminum sesquichloride-diethyl ether of diethylene glycol, the average amount of discharge in four sequential operations was 89.5 percent representing a gain in efliciency of over 18 percent, the range being from 87 to 91 percent discharged. A similar series using the catalyst system methyl aluminum sesquichloride and the dimethyl ether of diethylene glycol resulted in an average discharge efiiciency of 83 percent, or an improvement of about 12.5 percent. Accordingly, the present invention not only results in good yields of tetramethyllead, but aids the discharge of the products of the reaction from a reaction zone. Similar benefits are, of course incurred in techniques available for the continuous reaction of sodium lead alloy or methyl chloride to obtain tetramethylstandard procedure already described employing an alulfiai minum hydfffcal'bon Catalyst and toluene, 1101 1151118 To illustrate further the beneficial results obtained, with the synergestl co-catalyst COmPOIImt accofdlfig t0 the other examples of the co-catalysts employed according to present improvement. A determination was made, for the present process, the following examples give the reeach operation, of the quantity of the reaction mass dissults in an additional series of operations.

Aluminum hydrocarbon component Co-catalyst Hydro- TML Yield in- Example Catalyst carbon yield crease over Concentration Moles/gm. teed compon percent base line Identity Al, wt. percent Identity atom. Al ent, if any percent Alloy (0119 111 01 0.12 Dloxolaue 0.32 Normal. Toluene-.- 86.3 9.5 a 3 0.12 ---d o 1.07 (lo .-do----. 87.2 9.3 (011931112013 0.12 Ledloxane 2.60 ...do- ..do.--.. 80.0 3.2 (011103111101: 0.12 Dnlnetliyl ether of ethylene 0.85 -do ..do.... 96. 5 19. 7

g yco (CHahAlgCla 0.12 Diethyl ether of diethylene 1. 78 Delay.-- .d0.. 93. 5 16. 7

glycol and dioxolane 1 (CH3)3A1;C13-.-..----. 0.12 Dimethyl ether of ethylene 1.18 Normal. do. 91.0 14.2

glycol and dioxolane 2 1 (0 1193111 0. 12 Methyl ether of methyl tetra- About 1 Mixed.- do...- 93.9 About 15 hydrofuran.

1 Used in approximate equal volmne ratio. 2 Dioxolane in approximately percent volume concentration.

' lyst systems for the process.

In all the foregoing examples, the reaction masses obtained, prior to removal of the tetramethyllead therefrom, were relatively free-flowing, granular appearing materials. In contrast, in the base-line operations previously discussed, the reaction mixtures were relatively sticky and gummy, as shown by the information previously given on the efficiency of discharge. In addition, in all the above iven examples, the reaction masses did not exhibit fuming when exposed to the atmosphere.

To illustrate further additional catalyst combinations employed in other embodiments of the present invention, the following examples are typical illustrations of cata- When these catalyst systems are employed, similarly beneficial results are obtained.

Example Aluminum Co-catalyst Hydrocarbon component added, if any 27 (iO H )3Al. Dimcthyl other of Aromatic petroleum diethylcne glycol. cut. 28 (CuHiahAL. Dipropyl ether of None.

dicthylenc glycol. 29 (C Hn)aAl. Methyl ethyl ether Toluene.

of ethylene glycol. I 30 (O H )3Al Dibutyl ether of 2,2,4-trimethyl dicthylene glycol. hexane. 31 (C H9)2A1H- Dihcxyl other of 1,2-dimctl1yl ethylene glycol. benzene. 32 (Cali-hill-" Ethyl other of Propyl benzene.

methyl tetrahydroluran. 33 (CQH MALV Cyclohexyl ethyl None.

iether of dicthylene glycol. 34 (CH3)3A1- Phenyl ethyl di- Toluene.

ether of ethylene glycol.

Asadditional examples of catalyst components, which can be used as the second or synergistic catalyst component in place of these specially illustrated above, are:

' ployed.

cyclohexyl methyl ether of ethylene glycol, cyclopentyl butyl ether of triethylene glycol, diphenyl ether of tetraethylene glycol, butyl ether of methyl tetrahydrofuran, 2-methyl-l,4-dioxane, methyl dioxolane and others. Ad-

ditional examples of catalyst system components in which are used a plurality of compounds having thedesired glycol ether grouping, are mixtures of dimethyl ether of ethylene glycol and methyl ethyl ether of diethylene glycol, methyl ethyl ether of diethylene glycol with dioxolane, and numerous others.

The reasons for the highly beneficial results obtained by the present process are not fully understood. However, it appears that the efiective catalyst systems are actually new compositions representing complex materials between the hydrocarbon aluminum component :and the organo component having glycol other type linkages up to four or five moles per gram atom of aluminum in 1 the aluminum component. The absence of fuming upon formation of such complexes, either prior to utilization in the reaction for synthesizing tetramethylle-ad, or as evidenced by the attributes of the resultant reaction mass, is indicative of the absence of non-complexed hydrocarbon -aluminum bonds of moieties, in as much as these latter are well known to be quite reactive with atmospheric oxygen. Accordingly, the catalyst system employed under the present process represents new and novel compositions of matter utilizable for the indicated process, and also as alkylating agents for reaction with metal salts, or for convenient sources of hydrocarbon- 8 aluminum moieties. in an easily handled transportable form.

As evidenced fromthe examples above, the yields obtained generally representa significant improvement over the best yields in tetramethyllead synthesis heretofore encountered. Further, it is found that these yields are in excess of mere cumulative yields. Thus, when the dimethyl ether of ethylene glycol was employed in the proportions found eifective as a co-catalyst (Example 18) a yield of only 2% was obtained. When the dimethyl ether of diethylene glycol was employed, in the presence of toluene, the yields also encountered were quite low. The benefits of the process are significant not only in the high yields customarily realized but alsoin the attainment of good yields with a great reduction in the amount of aluminum type catalyst required.

As already shown, the glycol-type linkage containing component can be a single compound or can be, when desired, two or even more compounds. In fact, in some respects, further benefits are thus realized which are particularly advantageous in certain environments. Thus, in Example 24, an approximate equal volume mixture of diethyl ether of diethylene glycol and dioxolane was em- It is found that the rapidity of reaction in this instance is improved, particularly as evidenced by the speed at which a reaction is initiated. Thus, in the case of four operations using a catalyst system consisting of methyl aluminum sesquichl-oride and. the diethyl ether of diethylene glycol, the average time required before the reaction was proceeding at a realistic rate, after attainment of reaction temperatures, was 53 minutes. In contrast, in three operations wherein the catalyst system included methyl aluminum sesquichloride, and diethyl ether ofdiethylene glycol in conjunction with dioxolane, as in Example 24, the average time required to initiate reaction at a realistic rate was 31 minutes, representing an improvement of approximately 40 percent.

As previously noted, the present invention not only provides appreciable increase in yield of the maximum yields obtained when using aluminum catalyst as the sole catalyst component, but in'addition the yield increase is achieved when using appreciably lower amounts of aluminum-hydrocarbon catalyst. Thus, although the optimum proportions of aluminum catalyst heretofore have been, in certain systems, in the range of about 0.18- 0.22 weight percent of aluminum of the sodium lead alloy charged, the examples given above show a high degree of efiectiveness is obtained when using, typically, only half as much aluminum catalyst. It will be understood that, although the present invention is permissive of, and results in, lugh yields, even with low proportions of the aluminum component, than heretofore believed necessary, that a wide range of aluminum or aluminum compound concentration is permissive. Thus, the benefits of the invention are obtained when proportions of aluminum of from about 0.04 to about 0.25 weight percent of the alloy, are used. A preferred range is from about 0.08 to 0.15 weight percent.

The relative amount of the components of'the catalyst systems are not highly critical, but are frequently im portant. Highly effective results are obtained from the low proportions of aboutone-fourth mole per .gram atom of the aluminum in the aluminum-hydrocarbon catalyst component up to as high as five moles per gram atom of aluminum. In particular systems, the relative proportions are more important. In the case ofv alkyl aluminumchloride or trialkyl aluminum combinations with di-lower alkyl ethers of lower polyethylene glycols, an optimum proportion is found in the range of ,from onehalf to about two moles of the di-loWer alkyl ether per atom of aluminum. Thus, in the case of dimethyl ether of diethylene glycol with methyl aluminum scsquichloride, a mole ratio .of 1.35-1 resulted in a yield of 94.3 percent (Example 11), even though the aluminum concentration was less than one-tenth weight percent of the alloy. It was found that ratios above and below this level tended to decrease the yield obtained, although as exhibited by the examples, appreciable increase over the best results obtained solely with an aluminum hydrocarbon catalyst were nevertheless realized.

The mode of addition of the catalyst is sometimes important. In the case of a large number of operations using methyl aluminum sesquichloride in conjunction with the dimethyl ether of diethylene glycol, it was found that the yield was not sensitive to the mode of addition. On the other hand, when methyl aluminum sesquichloride and the diethyl ether of diethylene glycol were used together, it was found highly desirable to defer addition of some of the methyl aluminum sesquichloride for several minutes after a portion thereof, with the diethyl ether of diethylene glycol, had been introduced to the reaction zone. The preferred mode of addition for any explicit catalyst system is readily determinable.

We claim:

*1. The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl chloride in the presence of a catalyst system formed by adding an aluminum catalyst and at least one co-catalyst which is an organic compound consisting of carbon, hydrogen and oxygen, the aluminum catalyst being selected from the group consisting of aluminum,

aluminum trichloride,

aluminum tribromide,

aluminum triiodide, and

a hydrocarbon aluminum compound having at least one hydrocarbon group bonded to aluminum by a carbonaluminum linkage and selected from the group consisting of trihydrocarbon aluminum compounds, hydrocarbon aluminum chlorides, hydrocarbon aluminum hydrides, and hydrocarbon aluminum alkoxides, wherein the said hydrocarbon groups bonded to aluminum are hydrocarbon groups selected from the group consisting of alkyl, phenyl, and mixtures thereof, each co-catalyst being a compound having at least one glycol diether type group and being selected from the group consisting of dihydrocarbon ethers of lower polyethylene glycols having from two to seven glycol groups, dihydrocarbon ethers of ethylene glycol,

lower alkyl ethers of 1,4-dioxane,

1,4-dioxane,

clioxolane,

lower alkyl dioxolane, and

hydrocarbon ethers of methyl tetrahydrofuran, the hydrocarbon radicals of the said co-catalysts being radicals selected from the group consisting of alkyl, phenyl, cyclohexyl and mixtures thereof.

. 2. The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl chloride in the Presence of a catalyst I system formed by adding (A) an alkyl aluminum compound selected from the group consisting of aluminum trialkyls alkyl aluminum chlorides alkyl aluminum hydrides alkyl aluminum alkoxides, and (B) a lower alkyl dialkyl ether of a lower polyethylene glycol having from two to seven glycol groups, the alkyl radicals of the members of the above groups having up to about ten carbon atoms.

3. The process of claim 2 further defined in that (B) is the diethyl ether of diethylene glycol.

4. The process of claim 2 further defined in that (B) is themethyl ethyl ether-of diethylene glycol. I 5. The process of claim 2 further defined in that (B) is the dimethyl ether of diethylene glycol.

6. The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl chloride in the presence of a cata lyst system formed by adding an aluminum catalyst and at least one co-catalyst which is an organic compound consisting of carbon, hydrogen and oxygen, the aluminum catalyst being selected from the group consisting of aluminum,

aluminum trichloride,

aluminum tribromide,

aluminum triiodide, and

a hydrocarbon aluminum compound having at least one hydrocarbon group bonded to aluminum by a carbonaluminum linkage and selected from the group consisting of trihydrocarbon aluminum compounds, hydrocarbon aluminum chlorides, hydrocarbon aluminum hydrides, and hydrocarbon aluminum alkoxides, wherein the said hydrocarbon groups bonded to aluminum are hydrocarbon groups selected from the group consisting of alkyl, phenyl and mixtures thereof,

the said co-catalyst being a compound having at least one glycol diether type group and being selected from the group consisting of dihydrocarbon ethers of lower polyethylene glycols having from two to seven glycol groups, the hydrocarbon radicals of the said co-catalyst being radicals selected from the group consisting of alkyl, phenyl, cyclohexyl and mixtures thereof.

7. The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lea-d alloy and methyl chloride in the presence of a catalyst system formed by adding an aluminum catalyst and at least one co-catalyst which is an organic compound consisting of carbon, hydrogen and oxygen, the aluminum catalyst being selected from the group consisting of aluminum,

aluminum trichloride,

aluminum tribromide,

aluminum triiodide, and

a hydrocarbon aluminum compound having at least one hydrocarbon group bonded to aluminum by a carbon-aluminum linkage and selected from the group consisting of trihydrocarbon aluminum compounds, hydrocarbon aluminum chlorides, hydrocarbon aluminum hydrides, and hydrocarbon aluminum alkoxides, wherein the said hydrocarbon groups bonded to aluminum are hydrocarbon groups selected from the the group consisting of alkyl, phenyl and mixtures thereof,

each co-catalyst being a compound having at least one glycol diether type group and being selected from the group consisting of dihydrocarbon ethers of ethylene glycol, the hydrocarbon radicals of the said co-catalyst being radicals selected from the group consisting of alkyl, phenyl, cyclohexyl and mixtures thereof.

8. The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl chloride in the presence of a catalyst system formed by adding triethyl aluminum in proportions providing an aluminum concentration of from about 0.04 to 0.25 weight percent of the sodium lead alloy, and dimethyl ether of diethylene glycol in proportions of from about one-fourth to five moles per atom of aluminum 9. The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl chloride in the presence of a catalyst system formed by adding methyl aluminum sesquichloride in proportions providing an aluminum concentration of from about 0.04 to 0.25 weight percent of the sodium lead alloy, and dimethyl ether of diethylene glycol in proporareazao l l tions of from about one-fourth to five moles per atom of aluminum.

1%. The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl chloride in the presence of a catalyst system formedby adding methyl aluminum sesquichloride in proportions providing an aluminum concentration of from about 0.04 to 0.25 weight'percent of the sodium lead alloy, and diethyl ether-of diethylene glycol in proportions of from about one-fourth to five moles per atom of aluminum.

11. The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactantsa sodium lead alloy and methyl chloride in the presence of a catalyst system formed by adding methyl aluminum sesquichloride in proportions providing an aluminum concen-- tration of from about 0.04 to 0.25 weight percent of the sodium lead alloy, and methyl ethyl ether of diethylene glycol in proportions of from about one-fourth to five moles-per atom of aluminum.

' 12. "The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactants, a sodium lead alloy and methyl chloride in the presence of a catalyst. formed by adding (A) an alkyl aluminum compound selected from the group consisting of,

aluminum trialkyls,

alkyl aluminum chlorides,

alkyl aluminum hydrides,

alkyl aluminum alkoxides, and (B) a dialkyl ether of ethylene glycol, each alkyl group of the members of the foregoing additives having up to about ten carbon atoms.

13. The process of claim 12 further defined in that (B) is the dimethyl ether of ethylene glycol.

14. The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl. chloride in the presence of a catalyst system formed by adding methyl aluminum sesquichloride in proportions providing an aluminum concentration of from about 0.04 to 0.25 weight percent of the sodium lead alloy and dimethyl ether of ethylene glycol in proportions of from. about one-fourth to five moles per atom of aluminum.

15. The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl chloride in the presence of a catalyst system formed by adding an aluminum catalyst and at least one co-catalyst which is an organic compound consisting of carbon, hydrogen and oxygen, the aluminum catalyst being selected from the group consisting of aluminum,

aluminum trichloride,

aluminum tribromide,

aluminum triiodide, and

a hydrocarbon aluminum compound having at least one hydrocarbon group bonded to aluminum by a carbonaluminum linkage and selected from the group consisting of trihydrocarbon aluminum compounds, hydrocarbon aluminum chlorides, hydrocarbon aluminum hydrides, and hydrocarbon aluminum alkoxides, wherein the said hydrocarbon groups bonded to aluminum are hydrocarbon groups selected from the group consisting of allcyl, phenyl and mixtures thereof,

each co-catalyst being a compound having at least one glycol diether type group and being selected from the group consisting of lower alkyl ethers of 1,4 dioxane,

1,4-dioxane,

dioxolane, and

lower alkyl dioxolane.

16. The process of manufacture of tetrarnethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl chloride in the presence of a catalyst system formed by adding an alkyl aluminum com pound as hereafter defined, dimethyl ether of ethylene glycol and dioxolane, the alkyl aluminum compound being selected from the group consisting of aluminum trialkyls,

alkyl aluminum chlorides,

alkyl aluminum hydrides,

alkyl aluminum alkoxides, and each alkyl radical of the members of the above group having up to about ten carbon atoms.

1'7. The process of manufacture of tetramethyllead comprising reacting asessentially the sole reactants a sodium lead alloy and methyl chloride in the presence of a catalyst system formed by adding methyl aluminum sesquichloride in proportions providing an aluminum concentration of from about 0.04 to 0.25 weight percent of the 7 sodium lead alloy, and a mixture of the dimethyl ether of ethylene glycol anddioxolan in proportions of from about one-fourth to five moles of the mixture 'per atom of aluminum.

18. The process for manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl chloride in the presence of a catalyst system formed by adding an alkyl aluminum compound as hereafter defined, the diethyl ether of diethylene glycol, and dioxolane, the alkyl aluminum compound being selected from the group consisting of aluminum triallcyls,

alkyl aluminum chlorides,

alkylaluminum hydrides, and

alkyl aluminum alkonides, each allcyl radical of the members of the above group having up to about ten carbon atoms.

19. The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl chloride in the presence of a catalyst system formed by adding methyl aluminum sesquichloride in proportions providing an aluminum concentration of from about 0.04 to 0.25 weight percent of the sodium lead alloy, and a mixture of the diethyl ether of diethylene glycol and dioxolane in proportions of from about one-fourth to five moles of the mixture per atom of aluminum.

20. The improved process for manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl chloride in the presence of a catalyst system formed by adding (A) an alkyl aluminum compound and (B) a cyclic diether, both as hereafter defined, the alkyl aluminum compound (A) being selected from the groups consisting of,

aluminum trialkyls,

alkyl aluminum chlorides,

alkyl aluminum hydrides,

alkyl aluminumalkoxides, the alkyl groups thereof each having up to about ten carbon atoms, and the cyclic diether (B) being selected from the group con sisting of dioxolane, and,

1,4-dioxane.

21. The process of claim 20 further defined in that the cyclic diether is 1,4-dioxane.

22. The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl chloride in the presence of a catalyst system formed by adding methyl aluminum sesquichloride in proportions providing an aluminum concentration of from about 0.04 to 0.25 Weight percent of the sodium lead alloy and 1,4-dioxane in proportions of from about one-fourth to five moles per atom of aluminum.

23. The" process or manufacture of tetramethylleadv alkyl aluminum chlorides,

alkyl aluminum hydrides,

alkyl aluminum alkoxi cle, and (B) a lower alkyl ether of methyl tetrahydrofuran, each alkyl group of the foregoing additives having up to about ten carbon atoms.

24. The process of manufacture of tetramethyllead comprising reacting as essentially the sole reactants a sodium lead alloy and methyl chloride in the presence of a catalyst system formed by adding triethyl aluminum in proportions providing an aluminum concentration of from about 0.04 to 0.25 weight percent of the sodium lead alloy and methyl ether of methyl tetrahydrofuran in proportions of from about one-fourth to five moles per atom of aluminum.

25. The reaction mass derived from the process of claim 1 wherein the said sodium lead alloy is reacted 14 with methyl chloride in the presence of the said catalyst system of claim 1, the said reaction mass being characterized by the relative freedom from fuming and smoking when exposed to gaseous atmosphere having smoke ini tiating reactants therein.

References (Iited by the Examiner UNITED STATES PATENTS 2,905,646 9/59 Natta et a1. 252-431 2,985,594 5/61 Zimmerman 252--431 3,052,702 9/62 Robinson 260437 3,057,897 10/62 Robinson 260437 3,072,694 1/63 Tullio 260437 3,072,695 1/ 63 Tullio 260437 TOBIAS E. LEVOW, Primary Examiner. 

1. THE PROCESS OF MANUFACTURE OF TETRAMETHYLLEAD COMPRISING REACTING AS ESSENTIALLY THE SOLE REACTANTS A SODIUM LEAD ALLOY AND METHYL CHLORIDE IN THE PRESENCE OF A CATALYST SYSTEM FORMED BY ADDING AN ALUMINUM CATALYST AND AT LEAST ONE CO-CATALYST WHICH IS AN ORGANIC COMPOUND CONSISTING OF CARBON, HYDROGEN AND OXYGEN, THE ALUMINUM CATALYST BEING SELECTED FROM THE GROUP CONSISTING OF ALUMINUM, ALUMINUM TRICHLORIDE, ALUMINUM TRIBROMIDE, ALUMINUM RIIODIDE, AND A HYDROCARBON ALUMINUM COMPOUND HAVING AT LEAST ONE HYDROCARBON GROUP BONDED TO ALUMINUM BY A CARBONALUMINUM LINKAGE AND SELECTED FROM THE GROUP CONSISTING OF TRIHYDROCARBON ALUMINUM COMPOUNDS, HYDROCARBON ALUMINUM CHLORIDES, HYDROCARBON ALUMINUM HYDRIDES, AND HYDROCARBON ALUMINUM ALKOXIDES, WHEREIN THE SAID HYDROCARBON GROUPS BONDED TO ALUMINUM ARE HYDROCARBON GROUPS SELECTED FROM THE GROUP CONSISTING OF ALKYL, PHENYL, AND MIXTURES THEREOF, EACH CO-CATALYST BEING A COMPOUND HAVING AT LEAST ONE GLYCOL DIETHER TYPE GROUP AND BEING SELECTED FROM THE GROUP CONSISTING OF DIHYDROCARBON ETHERS OF LOWER POLYETHYLENE GLYCOLS HAVING FROM TWO TO SEVEN GLYCOL GROUPS, DIHYDROCARBON ETHERS OF ETHYLENE GLYCOL, LOWER ALKYL ETHERS OF 1, 4-DIOXANE, 1,4-DIOXANE, DIOXOLANE, LOWER ALKYL DIOXOLANE, AND HYDROCARBON ETHERS OF METHYL TETRAHYDROFURAN, THE HYDROCARBON RADICALS OF THE SAID CO-CATALYSTS BEING RADICALS SELECTED FROM THE GROUP CONSISTING OF ALKYL, PHENYL, CYCLOHEXYL AND MIXTURES THEREOF. 